Tibial resection systems and methods for cruciate ligament retainment

ABSTRACT

Tibial resection systems and methods for use in a uni- or bi-cruciate retaining knee replacement procedure are disclosed. A tibial resection system can include a tibial block, an alignment guide, and a tibial implant template. The tibial block can be coupled to an anterior side of a tibia and longitudinally extend from a proximal end portion to a distal end portion. The alignment guide can be coupled to the proximal end portion of the tibial block and can include one or more drill guides and a drill guide adjustment mechanism. The tibial implant template can be engaged with the drill guide adjustment mechanism, such that rotational movement of the tibial implant template can adjust an axial direction of the one or more drill guides. An outer profile of the tibial implant template can be selected to substantially match an outer profile of a tibial prosthesis to be implanted.

CLAIM OF PRIORITY

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/774,296, filed on Mar. 7, 2013, the benefit ofpriority of which is claimed hereby, and of which is incorporated byreference herein in its entirety.

TECHNICAL FIELD

This document pertains generally, but not by way of limitation, totibial resection systems and methods.

BACKGROUND

Retaining one or both of an Anterior Cruciate Ligament (ACL) and aPosterior Cruciate Ligament (PCL) in a knee replacement procedure canlead to shorter recovery times and a less invasive surgical procedure.

Existing systems and methods used to preserve an ACL or PCL during asurgical procedure, such as those disclosed in WO 2010/138854, WO2010/147797, and US 2010/0331848, are complex, can be difficult for asurgeon to use, and may not provide for stable or accurate bone cuts.

OVERVIEW

This patent document pertains generally to systems and methods that canbe used in a uni- or bi-cruciate retaining tibial resection procedure,such as during a total knee replacement surgery, in a more simplistic,stable, and accurate way than is currently available. The presentinventors recognize that existing cruciate retaining tibial resectionsystems and methods fail to provide a surgeon with the ability toaccurately produce a proximal tibial resection using a template,relating to a size or shape of a tibial prosthesis to be implanted, toorient one or more drill guides. The present inventors also recognizethat existing cruciate retaining tibial resection systems and methodsfail to provide a surgeon with the ability to produce a resected boneblock with a radiused corner on lateral, medial, and/or anterior sidesof the tibia. It is believed that radiused corners of the tibial boneblock can provide greater bone stability than stress-focusingsharp-edged corners.

Through the use of the present systems and methods, a surgeon canaccurately envision the proper size, shape, and/or placement of a tibialprosthesis that allows for retaining one or both the ACL and PCL.Because a tibial implant template can be engaged with a drill guideadjustment mechanism, which can form the basis of resection saw bladecuts, the correct placement of the saw blade cuts can be provided.

The present patent document also discloses systems and methods forensuring that edges and inside corners of a resected tibial bone blockare rounded or radiused, thereby providing greater bone stability. Achisel and mill guide and a chisel can be used to produce an anteriorcut in a tibial bone block. The chisel and mill guide used inconjunction with the chisel can ensure that an anterior inside cornercan be milled in a rounded manner. Use of the chisel as a forward stopcan prevent a mill from over cutting the tibial bone block.

To better illustrate the tibial resection systems and methods disclosedherein, a non-limiting list of examples is provided here:

In Example 1, a tibial resection system can comprise a tibial block, analignment guide, and a tibial implant template. The tibial block can becoupled to an anterior side of a tibia and longitudinally extend from aproximal end portion to a distal end portion. The alignment guide can becoupled to the proximal end portion of the tibial block and can includeone or more drill guides and a drill guide adjustment mechanism. Thetibial implant template can be engaged with the drill guide adjustmentmechanism, such that rotational movement of the tibial implant templateadjusts an axial direction of the one or more drill guides.

In Example 2, the tibial resection system of Example 1 can optionally beconfigured such that the proximal end portion of the tibial blockincludes a guide surface having a slot. The slot can extend in adirection perpendicular to the longitudinal extension of the tibialblock and can be configured to receive a coupling projection of thealignment guide.

In Example 3, the tibial resection system of Example 2 can optionally beconfigured such that the slot includes a T-shaped cross-section. Thecoupling projection can include a size and a shape engageable with theT-shaped cross-section.

In Example 4, the tibial resection system of any one or any combinationof Examples 1-3 can optionally be configured such that an outer profileof the tibial implant template substantially matches an outer profile ofa tibial prosthesis to be implanted.

In Example 5, the tibial resection system of any one or any combinationof Examples 1-4 can optionally be configured such that the tibialimplant template includes a plurality of tibial implant templates havingdiffering outer profile shapes or sizes.

In Example 6, the tibial resection system of any one or any combinationof Examples 1-5 can optionally be configured such that the tibialimplant template is sized and shaped to fit in situ between a proximalend of the tibia and a distal end of a femur, between medial and lateralcollateral ligaments, and partially around one or more cruciateligaments.

In Example 7, the tibial resection system of any one or any combinationof Examples 1-6 can optionally be configured such that the tibialimplant template includes one or more holes positioned to match alocation of one or more holes of a tibial prosthesis to be implanted.

In Example 8, the tibial resection system of any one or any combinationof Examples 1-7 can optionally be configured such that the alignmentguide comprises a first member, including the one or more drill guides,and a second member positioned proximally of the first member. The firstand second members can be pivotably connected and moveable, relative toone another, using the drill guide adjustment mechanism.

In Example 9, the tibial resection system of any one or any combinationof Examples 1-8 can optionally further comprise one or more guide pinsinsertable into one or more drill holes formed using the one or moredrill guides.

In Example 10, the tibial resection system of Example 9 optionallyfurther comprise a cutting guide, positionable on the one or more guidepins, including one or more vertical cut slots and one or morehorizontal cut slots.

In Example 11, the tibial resection system of Example 10 can optionallybe configured such that the one or more horizontal cut slots and the oneor more vertical cut slots are positioned to align with an outer surfaceof the one or more guide pins, when the cutting guide is positionedthereon.

In Example 12, the tibial resection system of any one or any combinationof Examples 1-11 can optionally further comprise a chisel and mill guidehaving a proximal end portion, including a pin projection and a curvedrecess wall; a distal end portion, positionable on a resected tibialsurface; and an anterior portion, including a mill recess.

In Example 13, the tibial resection system of Example 12 can optionallybe configured such that the pin projection is configured to receive amating void of a chisel handle and the curved recess wall is configuredto receive and guide a chisel blade.

In Example 14, the tibial resection system of any one or any combinationof Examples 12 or 13 can optionally be configured such that an extensionof the curved recess wall intersects with a depth of the mill recess.

In Example 15, a tibial resection method comprises attaching a tibialblock to a tibia; securing an alignment guide, including one or moredrill guides and a drill guide adjustment mechanism, to the tibialblock; selecting a tibial implant template to match a size or shape of aproximal end of the tibia; and engaging the selected tibial implanttemplate with the drill guide adjustment mechanism. The tibial resectionmethod can further comprise moving the selected tibial implant templateto a desired position on the proximal end of the tibia, includingadjusting an axial direction of the one or more drill guides; anddrilling one or more guide pin holes in the tibia using the one or moredrill guides.

In Example 16, the tibial resection method of Example 15 can optionallybe configured such that drilling the one or more guide pin holesincludes forming a radius corner of a resection cut.

In Example 17, the tibial resection method of any one or any combinationof Examples 15 or 16 can optionally further comprise removing thealignment guide; inserting a guide pin in each of the one or more guidepin holes; positioning a cutting guide on the one or more guide pins,including aligning one or more vertical cut slots and one or morehorizontal cut slots with an outer surface of the one or more guidepins; resecting tibial bone along the one or more vertical cut slots andthe one or more horizontal cut slots, including preserving an anteriorcruciate ligament and a posterior cruciate ligament; and removing thecutting guide.

In Example 18, the tibial resection method of Example 17 can optionallybe configured such that attaching the tibial block to the tibia includesestablishing a height of the one or more horizontal cut slots.

In Example 19, the tibial resection method of any one or any combinationof Examples 17 or 18 can optionally further comprise attaching a chiseland mill guide to the tibia, including positioning a first portion ofthe chisel and mill guide on a medial side of the anterior and posteriorcruciate ligaments and positioning a second portion of the chisel andmill guide on a lateral side of the anterior and posterior cruciateligaments.

In Example 20, the tibial resection method of Example 19 can optionallyfurther comprise chiseling an anterior portion of the proximal end ofthe tibia, including guiding a chisel distally along a pin projectionextending from a proximal end portion of the chisel and mill guide; and,after chiseling, milling a base of the anterior portion of the proximalend of the tibia, including guiding a milling tool along a mill recesson an anterior portion of the chisel and mill guide.

In Example 21, the tibial resection method of Example 20 can optionallybe configured such that guiding the milling tool along the mill recessincludes protecting a portion of the proximal end of the tibia using aportion of the chisel.

In Example 22, the tibial resection method of any one or any combinationof Examples 15-21 can optionally be configured such that selecting thetibial implant template includes sliding a tibial implant templatebetween the proximal end of the tibia and a distal end of a femur,between medial and lateral collateral ligaments, and partially aroundone or more cruciate ligaments.

These and other examples and features of the present tibial resectionsystems and methods will be set forth, in part, in the followingDetailed Description. This

Overview is intended to provide non-limiting examples of the presentsubject matter—it is not intended to provide an exclusive or exhaustiveexplanation. The Detailed Description below is included to providefurther information about the present tibial resection systems andmethods.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. Like numerals havingdifferent letter suffixes may represent different instances of similarcomponents. The drawings illustrate generally, by way of example, butnot by way of limitation, various embodiments discussed in the presentpatent document.

FIG. 1 illustrates a schematic view of a tibial block, in position for atibial resection procedure, and the advancement of an alignment guideonto a proximal end portion of the tibial block.

FIG. 2 illustrates an isometric view of an alignment guide.

FIG. 3 illustrates an isometric view of a tibial implant template.

FIG. 4 illustrates a schematic view of a tibial implant template and anadjustment of one or more drill guides included in an alignment guide.

FIG. 5 illustrates a schematic view of a drill advancing into a drillguide included in an alignment guide.

FIG. 6 illustrates a schematic view of a tibia including visible drillholes formed using drill guides, of an alignment guide, as the alignmentguide is removed.

FIG. 7 illustrates a schematic view of guide pins inserted into drillholes, which are formed using drill guides included in an alignmentguide.

FIG. 8 illustrates a schematic view of a cutting guide being positionedupon guide pins.

FIG. 9A illustrates a schematic view of a cutting guide, secured onguide pins, and saw blades for the creation of horizontal and verticalcuts.

FIG. 9B illustrates a close up plan view of a corner radius of a tibialbone block, formed by horizontal and vertical cuts that are aligned withan outer surface of a guide pin.

FIG. 10 illustrates a schematic view of a resected tibial bone block,with guide pins in place.

FIG. 11 illustrates a schematic view of a chisel and mill guide beinginstalled on a tibial bone block.

FIG. 12 illustrates a schematic view of a finished tibial bone block andretained cruciate ligaments.

FIG. 13 illustrates a top view of a chisel and mill guide.

FIG. 14 illustrates a schematic view of a chisel and mill guide pinnedin place and an advancing chisel.

FIG. 15 illustrates a schematic view of a chisel and a ball end mill,each of which is engaged with a chisel and mill guide.

FIG. 16 illustrates a plan view of a fluted chisel blade tip acting as atravel stop for a ball end mill.

FIG. 17 illustrates an isometric view of a cutting guide.

DETAILED DESCRIPTION

FIG. 1 illustrates a knee joint 94 including a distal end of a femur101, a proximal end of a tibia 93, and several ligaments, including ananterior cruciate ligament (ACL) 95 on a front side of the tibia 93. Aposterior cruciate ligament (PCL) is hidden, but is in an analogousposition to the ACL 95, on a back side of the tibia 93. A medialcollateral ligament (MCL) 97 is located on an inner side of the kneejoint 94 and a lateral collateral ligament (LCL) 98 is located on anouter side of the knee joint 94. The proximal end of the tibia 93 caninclude an uneven top surface and can have one or more protrusions inthe area of an intercondylar eminence 99.

A tibial resection system can include, among other things, a tibialblock 1, an alignment guide 21, and a tibial implant template 34 (FIG.3).

The tibial block 1 can be secured to an anterior side 100 of the tibia93. The connection can be accomplished by one or more tibial block pins17, for example. Alternatively, the tibial block 1 can be secured to thetibia 93 by screws, bolts, nails, or straps. The tibial block 1 caninclude a longitudinal extension 2 configured to provide verticalsupport to a horizontal member 18, located at a proximal end portion ofthe tibial block 1. The longitudinal extension 2 can include anadjustment slot 11 that can be used to adjust the position of the tibialblock 1 after a tibial block pin 17, or other securing means, has beeninstalled. The longitudinal extension 2 and the horizontal member 18 caninclude a plurality of attachment holes 12, which can be used to furthersecure the tibial block 1 to the tibia 93.

The horizontal member 18 of the tibial block 1 can include an alignmentguide retaining structure 20, which can be configured as a slot 4. Theslot 4 can take the form of an inverted “T” in cross-section, with abase 13 having a greater width than a neck region 19 and configured toreceive one or more coupling projections 30 on the alignment guide 21.In an alternative example, the mating structures can be reversed with a“T”-shaped rail disposed on the horizontal member 18 and a couplingprojection, such as a slot, in the alignment guide 21. The horizontalmember 18 can include a horizontal, planar guide surface 3. A tibialblock alignment structure 6 can be located on the horizontal member 18.The tibial block alignment structure 6 can engage a handle (not shown)to align the tibial block 1 with the tibia 93.

Once the tibial block 1 has been secured in a desired position, thealignment guide 21 can be positioned on the horizontal, planar guidesurface 3. A surgeon can position the alignment guide 21 at any positionalong the slot 4 and can use a relative position of the ACL 95 as aguide.

FIG. 2 illustrates an enlarged view of an alignment guide 21, relativeto the illustration of FIG. 1. The alignment guide 21 can include one ormore drill guides 31, which allow accurate placement of one or moredrill holes in the tibia 93. The one or more drill guides 31 can becoupled with a drill guide adjustment mechanism 27.

The drill guides 31 and the drill guide adjustment mechanism 27 togetherform a first member 25 of the alignment guide 21, which is disposeddistally of a second member 26 of the alignment guide 21. The secondmember 26 can provide a structural framework for the moving portions ofthe alignment guide 21, including the first member 25. In operation, thesecond member 26 can be secured to the tibial block 1 in a manner thatallows the first member 25 to move while the second member 26 remainsstationary. The alignment guide 21 can include a first tightening screw22 with a coupling projection 30 on its distal end. When the alignmentguide 21 has been disposed on the tibial block 1 and positioned asdesired, the first tightening screw 22 can be tightened and the secondmember 26 and the alignment guide 21 can no longer move relative to thetibial block 1. However, the first member 25 is still free to rotateabout an axis 14 and the drill guides 31 can be adjusted to a correctangular direction by movement of the drill guide adjustment mechanism27. When the proper angular position of the drill guides has beenachieved, a second tightening screw 23 of the alignment guide 21 can betightened and the drill guides 31 can be secured for a drill guidingoperation.

By way of example, the first tightening screw 22 can be a T-slot boltwhich, when tightened, secures the second member 26 to the tibial block1, but does not affect movement of the drill guides 31. The secondtightening screw 23, when tightened, can bear down upon a surface of thedrill guides 31 while causing a coupling projection 30 connected to thesecond member 26 to be lifted against a surface of the alignment guideretaining structure 20 (see FIG. 1). The drill guides 31 can then beimmovable between the second tightening screw 23 and the planar guidesurface 3 (see FIG. 1).

FIG. 3 illustrates a tibial implant template 34. The tibial implanttemplate 34 can be generally flat and planar and can be sized and shapedto fit between the proximal end of the tibia 93 and the distal end ofthe femur 101 (see FIG. 1). The tibial implant template 34 can includetwo regions, a body 44 and a long axis member 42.

The body 44 can be generally shaped to match the proximal end of thetibia 93. The outer profile 39 of the body 44, for example, can beshaped to match the shape of a tibial prosthesis (not shown) that asurgeon intends to implant during a knee surgical procedure. An innerprofile 40 of the body 44 can be shaped to accommodate the proximal endof the tibia 93, which can include an uneven surface and can have one ormore protrusions in the area of an intercondylar eminence 99 (see FIG.1). The inner profile 40 can also be shaped to allow placement of thetibial implant template 34 without disturbance to the ACL 95 (see FIG.1), such as by way of an ACL recess 46. Because the tibial implanttemplate 34 can be moved in a posterior direction until it approximatesthe placement of the tibial prosthesis, an opening between two arms 41allows for movement without disturbance to the ACL 95 (see FIG. 1). Thearms 41 can be configured in a pincer-like or forked formation and notonly allow a surgeon to envision the placement of a tibial prosthesis,but can also provide the surgeon with a method to visualize the distanceof a tibial prosthesis from a PCL.

The long axis member 42 can include an engagement mechanism 35 that canact in conjunction with a drill guide adjustment mechanism 27 (see FIG.2) to rotate one or more drill guides 31 (see FIG. 2).

A surgeon can use the outer profile 39 of the body 44 to envision aplacement of a tibial prosthesis to be implanted, and when the tibialimplant template 34 is in a position that the surgeon desires to placethe tibial prosthesis, the drill guides 31 can ensure that drilling ofguide pin holes is performed accurately. The tibial implant template 34can have numerous and varied sizes, shapes, and holes relating to sizes,shapes, and connection schemes of tibial prostheses to be implanted. Inthe present example, a hole 38 is provided in the tibial implanttemplate 34 where a hole would need to be drilled to install aparticular tibial prosthesis. A tibial prosthesis can include akeel-like structure on its distal surface. A slot 36, provided in thetibial implant template 34, can be used to visualize the keel position.

It should be noted that any number of positional indicators and aids canbe incorporated into the tibial implant template 34. A surgeon can haveavailable to him/her a set of differently sized tibial implant templates34 to accommodate differently sized bone structures. Tibial implanttemplate sets can also match features of specific tibia implantprosthesis types or models.

FIG. 4 illustrates an alignment guide 21 positioned on a tibial block 1.A tibial implant template 34 has been inserted between the proximal endof the tibia 93 and the distal end of the femur 101. An outer profile 39of the tibial implant template 34 is inside both of the MCL 97 and theLCL 98. An interior of the tibial implant template 34 is shaped so thatit does not disturb the ACL 95.

As shown, the tibial implant template 34 can be positioned so that anengagement mechanism 35 can rotate a drill guide adjustment mechanism 27to properly position one or more drill guides 31. The engagementmechanism 35 can be in the form of a slot to allow movement of thetibial implant template 34 in the anterior/posterior direction. Anyrotational movement of the tibial implant template 34, however, cancause the engagement mechanism 35 to rotate the drill guide adjustmentmechanism 27 and change the position of the one or more drill guides 31.During movement of the drill guides 31, the first tightening screw 22can be tightened. After proper positioning of the tibial implanttemplate 34, a second tightening screw 23 can be tightened and the drillguides 31 can be secured and ready for drill guiding operation.

FIG. 5 illustrates a drill (e.g., a drill bit) 28 advancing into a drillguide 31 of an alignment guide 21. The drill 28 can be used to createone or more holes 32 (see FIG. 6) in the proximal end of the tibia 93.

FIG. 6 illustrates the removal of an alignment guide 21 from a tibialblock 1. After tightening screws 22, 23 have been loosened, thealignment guide 21 can be removed. Drill holes 32 can then visible abovethe tibial block 1.

FIG. 7 illustrates two guide pins 29 installed in two drill holes 32.The guide pins 29 can rest upon a horizontal guide surface 3 of a tibialblock 1.

FIG. 8 illustrates a cutting guide 47 advancing towards two installedguide pins 29 and a horizontal guide surface 3 of a tibial block 1. Thecutting guide 47 can include one or more pin recesses 51 that mate andengage with the installed guide pins 29. The cutting guide 47 caninclude a main body 77 that can serve as the main structural unit of thecutting guide 47. The pin recesses 51 can be formed in the distalportion of the main body 77. One or more vertical cut slots 49 can guidea vertical saw blade 66 (see FIG. 9). The main body 77 can includemating body members 69 that engage the horizontal guide surface 3 whenthe cutting guide 47 is in place on the tibial block 1. Lateralextensions 76 can extend outwardly on both sides of the main body 77 andcan be configured to not touch the horizontal guide surface 3, therebyforming a horizontal cut slot 48, when the cutting guide 47 isinstalled, to guide a horizontal saw blade 67 (see FIG. 9).

After the cutting guide 47 has been lowered, the pin recesses 51 canrest against the installed guide pins 29 and the mating body members 69can rest against the horizontal guide surface 3. The cutting guide 47can be secured into the alignment guide retaining structure 20 bypushing distally on a bolt handle 57 against pressure provided by aspring 63. Other resilient means could be provided in this location,such as a flat spring or a rubber bushing. After the bolt handle 57 hasbeen depressed, it can be rotated (e.g., 90 degrees) and a bolt plate 64can engage the alignment guide retaining structure 20. The bolt plate 64can be disposed at the distal end of a bolt 58, which passes through abolt hole 59 in the main body 77. The bolt can be threaded (not shown)in a proximal portion. The bolt can also pass through a washer 62 orother structure used as a distal resting surface for the spring 63. Thenut 60 can include internal threads (not shown) that mate with thethreads of the bolt 58. The bolt plate 64 and the bolt 58 can have awidth that is narrow enough to be vertically plunged into the neckregion 19 of the slot 4. The bolt plate 64 can have a length longer thanthe opening of the neck region 19 of the slot 4. The bolt plate 64 canbe connected to the bolt 58, which is connected to the bolt handle 57.When the bolt handle is 57 rotated (e.g., rotated 90 degrees), the boltplate length can engage the surfaces of the alignment guide retainingstructure 20. After the bolt plate 64 has been rotated into position,the nut 60 can be rotated until it tightens against a proximal surface65 of the main body 77. This action can tighten the bolt plate 64against the alignment guide retaining structure 20 and the cutting guide47 can be secured and ready for use. The cutting guide 47 can have adetent 53 to provide a position stop for the bolt handle 57 or thecutting guide 47 can have other positioning means, such as a marker, toshow that the bolt plate 64 is ready for removal or tightening. Thelengthwise direction of the bolt plate 64 can be aligned with thelengthwise direction of the bolt handle 57 as a positioning means.

FIG. 17 illustrates a closer view of the cutting guide 47, asconstructed in accordance with at least one example. A lengthwisedirection of the bolt plate 64 can be in a position that is transverseto a direction of the slot 4 (see FIG. 8). A locking washer 117 canprevent the bolt handle 57 from further rotation when it contacts alocking bar 119. If the bolt handle 57 is depressed, the locking washer117 can pass through the washer recess 118 and the lengthwise directionof the bolt plate 64 can be aligned with the lengthwise direction of theslot 4 (see FIG. 8).

FIG. 9A illustrates a cutting guide 47 secured in place on top of atibial block 1. A horizontal saw blade 67 can be used to make ahorizontal cut 78 in the proximal end of the tibia 93 and a vertical sawblade 66 can be used to make a vertical cut 73 (see FIG. 9B) in thetibia 93. The cut slots 48, 49 can be positioned so that when a cut isbeing made, installed guide pins 29 provide a stop for the saw blades66, 67.

The cut slots can be positioned so that the horizontal saw blade 67intersects a guide pin 29 near its distal outer surface and the verticalsaw blade 66 intersects the guide pin on its outer surface positionedadjacent to the center of the tibia 93. FIG. 9B shows a detail of how avertical cut 73 and a horizontal cut 78 can relate to outer surfaceportion of a guide pin 29. The finished cut can provide a smoothtransition between a drill hole, into which the guide pin 29 ispositioned, and the saw blade cuts, thereby giving the finished tibialbone block 104 (see FIG. 12) a smooth radius on an inside corner 110.

FIG. 10 illustrates a completed horizontal cut 78 and a completedvertical cut 73 with guide pins 29 and a cutting guide 47 remaining inan installed position. Resected bone pieces (not shown) of the tibial 93have been removed. The cutting guide 47, tibial block 1, and guide pins29 can now be removed.

FIG. 11 illustrates an installation of a chisel and mill guide 79 onto aresected tibia 93. The chisel and mill guide 79 can be used to finish aformation of a tibial bone block 104 by forming an area anterior to theACL 95, where a portion of a tibial prosthesis connecting medial andlateral prosthesis portions can be disposed without disturbance to abone connection of the ACL 95.

FIG. 12 represents an example of a finished tibial bone block 104. Thechisel and mill guide 79, in conjunction with a chisel and a mill, canform an anterior horizontal surface 107 that matches a proximal heightof horizontal cuts 78, and a curved vertical surface 106 that is themost anterior vertical surface of the finished tibial bone block 104.The chisel and mill guide 79 can also aid in forming a curved insideradiused corner 108, which joins the curved vertical surface 106 and theanterior horizontal surface 107.

Returning to FIGS. 11 and 13, the chisel and mill guide 79 can include aset of guide arms 91 configured to fit between the tibia 93 and thefemur 101 and around the resected cuts in the tibia. A pin protrusion 80and a chisel recess 81 can form a rigid placement mechanism for a chisel109 (shown in FIG. 14). A set of nail holes 92 can be included in theguide arms 91 for the securement of the chisel and mill guide 79 to thetibia 93. A mill guide 82 can be configured to aid in milling ananterior horizontal surface 107 (see FIG. 12) and a curved insideradiused corner 108 (see FIG. 12). The chisel and mill guide 79 caninclude radiused mating edges 83 on the guide arms 91, which fit closelyto a vertical cut 73 and an internal corner 110, while a lower surfaceof the arms 91 rests on the completed horizontal cut 78.

As shown in FIG. 13, the mill guide 82 can be configured with a furthestreach 112, which can be slightly past a junction 113 of the curvedrecess 81 and the straight internal portion of the guide arms 91. Theradiused mating edge 83 does not extend to the junction 113 so that atip of a ball end mill can be inserted in a posterior direction farenough to form a smooth transition between the inside corner radius 110and the curved inside corner radius 108.

FIG. 14 illustrates a chisel and mill guide 79 placed on a resectedproximal tibia 93 and as far posterior as a surgeon determines a chiselcut should be made. The chisel and mill guide 79 can be secured to thetibia 93 by screws, pins, nails, or other means and is shown secured bynails 105. A chisel 109 can include a blade 85 and a handle 84. Itshould be noted that in this example a chisel recess 81 is shown ascurved, but it can take other shapes. The back of the blade 85 can matewith the chisel recess 81 as a mating void 86 is engaged with a pinprotrusion 80. The chisel 109 can be secured in each direction exceptfor slidable movement upon the pin protrusion 80.

FIG. 15 illustrates a chisel 109 after it has been advanced into itsfinal position and has cut a curved vertical surface 106 (see FIG. 12)of the tibia 93. The chisel handle 84 can be configured to withstandimpact blows. Pins 105 can be used to retain the chisel and mill guide79 and the pin protrusion 80 can aid in locating and retaining thechisel 109. A mating void 86 can have a depth limitation structure 90that prevents the chisel 109 from further cutting movement when thedepth limitation structure 90 abuts a body proximal face 114 of thechisel and mill guide 79. The depth limitation structure 90 can also bedisposed at other locations on the chisel 109. With the chisel 109 atthe limited depth, a mill 89 can be inserted into a mill guide 82 andbone material can be removed that is anterior of the chisel 109 andproximal to the height of the horizontal cuts 78. The mill guide 82 canbe formed so that the milled cut will match the horizontal cuts 78. Themill 89 can have a rounded cutting end so that it will form an insideradiused corner. A back 116 of the chisel 109 can be used as a millstop. At the medial and lateral edges of a chisel blade 85, the mill 89would no longer be stopped, but can have a mill limit 111 on the mill 89to prevent the mill from entering the tibial bone block 104, by abuttingthe mill guide 82. As recited above, a cutting guide 47 can allow afinal reach 112 (see FIG. 13) so that the mill 89 can enter the millguide 82 far enough to provide a smooth transition between the insidecorner radius 110 and the curved inside corner radius 108 (see FIG. 11).

FIG. 16 illustrates a close up plan view of a mill 89 with an anteriorface of a chisel tip 88 of the chisel blade 85 acting as a cutting stop115 to prevent the mill 89 from entering a tibial bone block 104. Thechisel tip 88 can have a fluted anterior face 87 that aids the mill 89in locating to a correct depth for cutting the radiused curved insidecorner 108. The horizontal cut is shown at 78. Bone that is beingremoved is depicted by the dashed line and element numeral 120.

The above Detailed Description includes references to the accompanyingdrawings, which form a part of the Detailed Description. The drawingsshow, by way of illustration, specific embodiments in which the presenttibial resection systems and methods can be practiced. These embodimentsare also referred to herein as “examples.” Such examples can includeelements in addition to those shown or described. However, the presentinventors also contemplate examples in which only those elements shownor described are provided.

The above Detailed Description is intended to be illustrative, and notrestrictive. For example, the above-described examples shown ordescribed (or one or more elements thereof) can be used in combinationwith each other. Other embodiments can be used, such as by one ofordinary skill in the art upon reviewing the above description. Also,various features or elements can be grouped together to streamline thedisclosure. This should not be interpreted as intending that anunclaimed disclosed feature is essential to any claim. Rather, inventivesubject matter can lie in less than all features of a particulardisclosed embodiment. Thus, the following claims are hereby incorporatedinto the Detailed Description, with each claim standing on its own as aseparate embodiment. The scope of the invention should be determinedwith reference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of “at least one” or “one or more.” In thisdocument, the term “or” is used to refer to a nonexclusive or, such that“A or B” includes “A but not B,” “B but not A,” and “A and B,” unlessotherwise indicated. In this document, the terms “including” and “inwhich” are used as the plain-English equivalents of the respective terms“comprising” and “wherein.” Also, in the following claims, the terms“including” and “comprising” are open-ended, that is, a system, device,article, composition, formulation, or process that includes elements inaddition to those listed after such a term in a claim are still deemedto fall within the scope of that claim. Moreover, in the followingclaims, the terms “first,” “second,” and “third,” etc. are used merelyas labels, and are not intended to impose numerical requirements ontheir objects.

In the appended claims, the terms “including” and “in which” are used asthe plain-English equivalents of the respective terms “comprising” and“wherein.” The terms “including” and “comprising” are open-ended, thatis, a system, kit, or method that includes elements in addition to thoselisted after such a term in a claim are still deemed to fall within thescope of that claim. Moreover, in the following claims, the terms“first,” “second,” and “third,” etc. are used merely as labels, and arenot intended to impose numerical requirements on their objects.

The Abstract is provided to allow the reader to quickly ascertain thenature of the technical disclosure. It is submitted with theunderstanding that it will not be used to interpret or limit the scopeor meaning of the claims.

What is claimed is:
 1. A tibial resection system, comprising: a tibialblock, couplable to an anterior side of a tibia, longitudinallyextending from a proximal end portion to a distal end portion; analignment guide, couplable to the proximal end portion of the tibialblock, including one or more drill guides and a drill guide adjustmentmechanism; and a tibial implant template, engageable with the drillguide adjustment mechanism such that rotational movement of the tibialimplant template adjusts an axial direction of the one or more drillguides.
 2. The system of claim 1, wherein the proximal end portion ofthe tibial block includes a guide surface having a slot, the slotextending in a direction perpendicular to the longitudinal extension ofthe tibial block and configured to receive a coupling projection of thealignment guide.
 3. The system of claim 2, wherein the slot includes aT-shaped cross-section, and wherein the coupling projection includes asize and shape engageable with the T-shaped cross-section.
 4. The systemof claim 1, wherein an outer profile of the tibial implant templatesubstantially matches an outer profile of a tibial prosthesis to beimplanted.
 5. The system of claim 1, wherein the tibial implant templateis sized and shaped to fit in situ between a proximal end of the tibiaand a distal end of a femur, between medial and lateral collateralligaments, and partially around one or more cruciate ligaments.
 6. Thesystem of claim 1, wherein the tibial implant template includes one ormore holes positioned to match a location of one or more holes of atibial prosthesis to be implanted.
 7. The system of claim 1, wherein thealignment guide comprises a first member, including the one or moredrill guides, and a second member positioned proximally of the firstmember, the first and second members pivotably connected and moveable,relative to one another, using the drill guide adjustment mechanism. 8.The system of claim 1, further comprising one or more guide pinsinsertable into one or more drill holes formed using the one or moredrill guides.
 9. The system of claim 8, further comprising a cuttingguide, positionable on the one or more guide pins, including one or morevertical cut slots and one or more horizontal cut slots.
 10. The systemof claim 9, wherein the one or more horizontal cut slots and the one ormore vertical cut slots are positioned to substantially align with anouter surface of the one or more guide pins, when the cutting guide ispositioned thereon.
 11. The system of claim 1, further comprising achisel and mill guide having a proximal end portion, including a pinprojection and a curved recess wall; a distal end portion, positionableon a resected tibial surface; and an anterior portion, including a millrecess.
 12. The system of claim 11, wherein the pin projection isconfigured to receive a mating void of a chisel handle and the curvedrecess wall is configured to receive and guide a chisel blade.
 13. Thesystem of claim 11, wherein an extension of the curved recess wallintersects with a depth of the mill recess.
 14. A tibial resectionmethod, comprising: attaching a tibial block to a tibia; securing analignment guide, including one or more drill guides and a drill guideadjustment mechanism, to the tibial block; selecting a tibial implanttemplate to substantially match a size or shape of a proximal end of thetibia; engaging the selected tibial implant template with the drillguide adjustment mechanism; moving the selected tibial implant templateto a desired position on the proximal end of the tibia, includingadjusting an axial direction of the one or more drill guides; anddrilling one or more guide pin holes in the tibia using the one or moredrill guides.
 15. The method of claim 14, wherein drilling the one ormore guide pin holes includes forming a radius corner of a resectioncut.
 16. The method of claim 14, further comprising: removing thealignment guide; inserting a guide pin in each of the one or more guidepin holes; positioning a cutting guide on the one or more guide pins,including aligning one or more vertical cut slots and one or morehorizontal cut slots with an outer surface of the one or more guidepins; resecting tibial bone along the one or more vertical cut slots andthe one or more horizontal cut slots, including preserving an anteriorcruciate ligament and a posterior cruciate ligament; and removing thecutting guide.
 17. The method of claim 14 wherein attaching the tibialblock to the tibia includes establishing a height of the one or morehorizontal cut slots.
 18. The method of claim 14, further comprisingattaching a chisel and mill guide to the tibia, including positioning afirst portion of the chisel and mill guide on a medial side of theanterior and posterior cruciate ligaments and positioning a secondportion of the chisel and mill guide on a lateral side of the anteriorand posterior cruciate ligaments.
 19. The method of claim 18, furthercomprising: chiseling an anterior portion of the proximal end of thetibia, including guiding a chisel distally along a pin projectionextending from a proximal end portion of the chisel and mill guide; andafter chiseling, milling a base of the anterior portion of the proximalend of the tibia, including guiding a milling tool along a mill recesson an anterior portion of the chisel and mill guide.
 20. The method ofclaim 14, wherein selecting the tibial implant template includes slidinga tibial implant template between the proximal end of the tibia and adistal end of a femur, between medial and lateral collateral ligaments,and partially around one or more cruciate ligaments.